yukicoder_score9_sample.cpp

#include <iostream>
using namespace std;

long long N;
long long A[59];
long long B[59];

int main() {
	// Step 1. 入力
	cin >> N;
	for (int i = 1; i <= N; i++) cin >> A[i] >> B[i];

	// Step 2. 出力
	cout << N - 1 << endl;
	for (int i = 1; i <= N - 1; i++) {
		cout << 1 << " " << i + 1 << endl;
	}
	return 0;
}